Method of connecting multiphase windings.



'PATENTED APR. 28, 1903.-

w. s. MOODY. METHOD OF CONNECTING MULTIPHASE WINDINGS.

APPLIQATION FILED APR. 26, 19 02.

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I VELMTOQ WaICeh S. oocLy UNITED STATES PATENT OFFICE.

IVALTER S. MOODY, OF SCI-IENEOTADY, NEW YORK, ASSIGNOR TO GEN ERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD OF CONNECTING MULTIPHASE WINDINGS.

SPECIFIGATION forming part of Letters Patent No. 726,831, dated April28, 1903.

Original application filed February 3. 1902. Serial No. 92,332. Dividedand this application filed April 26, 1902. Serial No.104,892. (Nomodel.)

To 60% whom it may concern:

Be it known that I, WALTER S. MOODY, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Methods of ConnectingMultiphase Windings, of which the following is a specification.

This application is a division of my prior '10 application, Serial No.92,332, filed February My invention has reference to the connection ofmultiphase windings in delta in such a manner that voltages differentfrom the source of supply ordifferent from the voltages across theterminals of the several win dings may be readily obtained.

In a more specific aspect my invention contemplates the connection ofmultiphase windings in delta in such a manner that varying voltages maybe obtained therefrom.

In the accompanying drawings, Figure 1 illustrates a plurality ofmultiphase windings, together with one arrangement of switch contactsand connections which may be used in' practicing my invention. Figs. 2to 4, inclusive, are diagrams illustrating the character of theconnections made by the switch of Fig. 1.

o Referring to Fig. l of the drawings, T, T and T indicate a pluralityof transformers. The primary windings P of these transformers arearranged to be connected to a source of three-phase current through theconduc- 5 tors d, e, and f. The secondary winding S of each of thetransformers is provided with a plurality of taps 1 to b, inclusive, thetaps 1 and 6 being connected to terminal points in the windings and thetaps 2 to 5 being con- 0 nected to intermediate points therein. Fromthese taps in each of the transformer secondaries conductors 1 to 6 leadto a set of contacts on a switch D, by means of which the windings maybe connected in accordance 5 with the principles of my presentinvention. The conductors leading from the taps of the secondary windingof the transformer T are connected to the set of switch-contacts 1 to 6,inclusive, the conductors leading from the taps of the secondary windingof the transformer T are connected to the set of contacts 1 to 6", andthe conductors leading from the taps of the secondary winding of thetransformer T are connected to the set of contacts 1 to 6". In each ofthese sets the contacts 2 to 6, inclusive, are arranged in the arc of acircle, while the contacts 1, 1 and 1 are displaced therefrom andarranged in the arc of a circle of a different radius in order that themovable members of the switches may engage therewith in such a manner asto make the desired connections. The movable member of the switch Dcomprises three arms A B O, insulated from one another and arranged toconnect each one of the contacts 1, 1 and 1 with any one of the contacts2 to 6, inclusive, of one of the other sets. The switch handle H may beprovided with a pawl (not shown) arranged to engage one of the notchesin the member E in each of the positions of the switch. A system ofconductors g, h, and 1' leads from the contacts of the switch D to thetranslating devices (not shown) to which current is to be supplied.

In order that the operation of the switch may be understood, let it besupposed that the handle H is moved to bring the switchcontacts intotheir first operative position, with the movable contact A connectingthe fixed contacts 1" and 2, the movable contact B connecting fixedcontactsl and 2 and the movable contact 0 connecting the fixed contacts1 and 2 With the switch-contacts in this position the secondary windingsof the three transformers will be connected in delta with the portionbetween the taps 1 and 2 of each winding included in the deltaconnection, the point 2 in the winding of the transformer T beingconnected to the point 1 in the transformer T the point 2 in the trans-0 former T being connected to the point 1 in p the transformer T andpoint 2 in transformer T being connected to point 1 in transformer T.Also the several conductors g, h, and 1. will be connected to the apicesof the delta connection. The character of the connections completed inthis first position of the switch will be more clearly appreciated froman inspection of Fig. 2, which illustrates the connections abovedescribed. If new the 101..

handle of the switch D is moved to bring the members A, B, and G intothe second operative position, the connections illustrated in thediagram in Fig. 3 will be completed and in each of the succeedingpositions of the switch the size of the delta, and therefore thevoltages across the terminals thereof, will be successively increasedstep by step until in the last position of the switch, when the membersA, B, and G are in a position to connect contact 1 to 6, contact 1 to6", and contact 1 to 6, the total length of each of the several windingswill be included in the delta connection, as illustrated in Fig. 4. Froman inspection of the diagrams, Fig. 2 to 4, inclusive, it will be notedthat the system of conductors g, h, and t' is always connected to theapices of the delta in whatever position the switch D may be placed.

In Fig. 1 the windings which are connected in delta are the secondarywindings of a plurality of transformers; but evidently my invention isnot limited to the particular application which is illustrated in thisfigure, and in the diagram of Fig. 2 I have shown in dotted lines thateach of the separate windings, which are arranged to be connected indelta by the switch, may be supplied with current directly from asuitable source through the conductors d ef, corresponding to theconductors (l, e, and f of Fig. 1. Moreover, I desire it to beunderstood that my invention is not limited to transformer-windingsalone, but may be used in connection with multiphase windings of anycharacter whatsoever. Further, in its application to the windings of aplurality of transformers my invention may evidently be applied with theconnections the reverse of those above described-that is, with theconductors g, h, and '6 connected to a suitable source of three-phasecurrent and with the conductors d, e, andf leading to the translatingdevices which are intended to be supplied with current therefrom. Alsoit is to be understood that my invention is not limited to theconnection of three-phase windings, and in the claims hereto appended Ihave used the terms delta and delta connection to include any similarconnection of any number of multiphase windings.

What- I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. The method of obtaining voltages differing from the voltages acrossthe terminals of a plurality of multiphase windings which consists incompleting a delta connection including a portion only of each of saidwindings.

2. The method of obtaining voltages dilfering from the voltages acrossthe terminals of a plurality of multiphase windings which consistsinconnecting said windings in delta with one terminal of each of saidwindings connected to an intermediate point in another winding.

3. The method of obtaining variable voltages from a plurality ofmultiphase windings which consistsin connecting said windings in deltaand varying the lengths of the windings included in the deltaconnection.

4. The method of obtaining variable voltages from a plurality ofmultiphase windings which consists in connecting said windings in deltawith one terminal of each winding connected to an intermediate point inanother winding and shifting the points of connection of the saidwindings.

5. The method of obtaining variable voltages from a plurality ofmultiphase windings which consists in connecting said windings in deltawith one terminal of each winding connected to an intermediate point inanother winding and varying the lengths of the windings included in thedelta connection.

In witness whereof I have hereunto set my hand this 25th day of April,1902.

WALTER S. MOODY.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

